Earth-working machines, such as excavators, wheel loaders, electric cable shovels, and front shovels, include implements generally used for digging into, ripping, or otherwise moving earthen material. These implements are subjected to extreme abrasion and impacts that causes them to wear. To prolong the useful life of the implements, various ground engaging tools can be connected to the earth-working implements at areas experiencing the most wear. These ground engaging tools are replaceably connected to the implements using a retention system.
An exemplary retention system is disclosed in U.S. Patent Publication 2011/0072693 of Knight that published on Mar. 31, 2011 (“the '693 publication”). Specifically, the '693 publication discloses a fork-shaped tool body that fits over the edge of an excavator bucket. A clamp passes through the body and the bucket, and a wedge is inserted alongside the clamp to hold the clamp in position. The wedge has a U-shaped axial recess, and a threaded rod is received within the recess and oriented at an angle relative to the clamp. A threaded block is mounted to the rod, and the rod is rotatable to move the block along the rod. The block includes teeth that engage the clamp upon insertion of the wedge into the body, such that as the rod is rotated and the block moves along the rod, the wedge is forced further into the body. As the wedge is forced further into the body, the clamp is urged tighter against the body and the bucket. A resilient cap makes a friction fit with an end of the rod after assembly, thereby inhibiting inadvertent rotation of the rod. With this configuration, the fork-shaped tool body can be removably connected to the excavator bucket by rotation of the rod.
Although acceptable for some applications, the retention system of the '693 publication may be less than optimal. In particular, the toothed engagement between the block and the clamp may be a costly feature that has geometry that is difficult to control during manufacturing. In addition, after a period of wear, the clamp may become loose, requiring further adjustment of the rod. In some situations, the amount of adjustment required to tighten the joint may require replacement of the clamp with a different size of clamp, which can be expensive for an owner of the machine. Further, as the retention system wears and is adjusted, it may be possible for the wedge to be moved too far into the tool body, making replacement difficult.
The disclosed tool retention system is directed to overcoming one or more of the problems set forth above.